In recent years, a variety of hybrid vehicles have been developed to improve the fuel efficiency of the vehicles, for example, and some of such hybrid vehicles include an automatic transmission that changes the speed of rotation of an internal combustion engine during hybrid travel and engine travel (see Patent Document 1).
For the hybrid vehicle including an automatic transmission according to Patent Document 1, it is proposed to engage a first clutch (C−1) when lower shift speeds (for example, first to third forward speeds) are determined, and disengage the first clutch (C−1) when higher shift speeds (for example, fourth to sixth forward speeds) are determined, to bring the automatic transmission into a neutral state during EV travel performed by only the drive force of a motor/generator (hereinafter referred to simply as a “motor”) with an internal combustion engine stopped.
In the automatic transmission for the hybrid vehicle described above, an output side (wheel side) member in the automatic transmission is rotated in an accompanying manner during EV travel, and therefore an electric oil pump is driven to supply lubricating oil to the automatic transmission.